1. Field of the Invention
This invention relates to ammunition and is particularly directed to caseless ammunition formed by molding multiple layers of propellant about the sides and rear of a projectile.
2. Prior Art
Heretofore, it has been conventional for ammunition, especially small arms ammunition, to comprise a metal cartridge or shell case containing a projectile and a quantity of propellant. Generally, the propellant was granular and the metal case, which was usually formed of brass, served to retain the propellant and to protect the propellant against mechanical shock and atmospheric degradation due to moisture, heat and the like. Unfortunately, brass is expensive and, especially during wartime, is often difficult to obtain. Moreover, the metal adds considerably to the weight of the ammunition, yet contributes nothing to its performance.
In order to overcome these disadvantages, it has been suggested that the metal cartridge cases be replaced by cases made of nitrocellulose. However, it has been found that these materials tend to ignite inadvertently, as when placed in a hot gun or when adjacent rounds of ammunition are ignited. More recently, with the development of castable solid propellants, such as are used in rocket motors and the like, it has been suggested that single grain propellants could be cast about the projectile to eliminate the need for metal cartridge cases. Unfortunately, those propellant materials which satisfy the mechanical and atmospheric requirements are either subject to the same disadvantages as the nitrocellulose cartridge cases or yield greatly reduced performance. Thus, none of the prior art techniques for providing caseless ammunition have been entirely satisfactory.